William me



Patented June 21, 1927.

W'ILLIAIMlI name, or swan, sew was,

' or EDGEWKTER rARk; JERSEY,

PATENT GFFICE,

assmsea re mam. uremia,

raocnss 13mins nmmnms AND Frame Fommn rnou vrseosn.

Filaments and films are ordinarily formed by coagulating viscose(sulphocarbonate) to cellulose hydrate by suitable chemical solutions,and such products may be satisfactorily colored by sulphur dyes and dyesof other classes, preferably what are known as such filaments and filmsduring the process of manufacture, so far as 1 am aware, thedifficulties in the way of such accomplisln ment have heretofore proveninsurmountable, because any attempt to dye such prod-- uots during theirmanufacture is defeated by interference of alkali or acid or sulphur orsulphur bearing compounds carried by the products.

Therefore, an object and effect of my invention is to provide a methodand means whereby such cellulose hydrate products may be successfullydyed during their process of'manufacture. I

After an extended research both for a solution to the problem of dyeingaforesaid and the problem of removing sulphur bearing impurities fromthe coagulated and precipitated cellulose hydrate; I have discoveredthat the action of PO, ions of tri-sodium phosphate (Na ,PO,) on thecellulose hydrate either previous to or coincident with the dyeing ofthe latter, removes all of the complexes injurious to direct dyes,

i. e., dyes whichare effective without the use of a mordant, or specialalkaline or acid solutions, and that, therefore, theimpure cellulosehydrate filaments or films may be satisfactorily dyed by either (1)treating them with said tri-sodium phosphate in aqueous solution beforesubjecting them to the action of'the dye, or (2) by treating them with asingle solution including such tri-sodium phosphate and the dye. v

This application includes claims limited to the second named procedure,and the other alternative procedure aforesaid is claimed in my copendingapplication Serial No. 32,450,. filed May 23, 1925. As an example of thespecies of my invention herein claimed; I coagulate viscose to form afilament of impure cellulose hydrate, byany 'mersing it in aqueous soApplication filed May 23, m seri l Np. $2,451.-

suitable means, and subject said filament to the action of tri-sodiumhosphate by imlhtion containing, say, three per cent thereof, and say,two per cent of direct black dye. Such percentages may be employed withany other direct dye of any color, shade or tint. Said percentages areconveniently calculated with reference to the dry weight of the finishedfilaments. I find it convenient to retain the filament in such bathuntil the dye is exhausted, say, from one and ahalf to two hours; whilemaintaining the same at from 50 to 100 0.; in accordance with the kindof dye used; certain direct dyes being more efficient at the highertemperature aforesaid, whereas, certain sulphur dyes are more effectiveat lower temperatures.

The effect of such treatment is to change to soluble form the freesulphur and insolublesulphides which are left in and adherent upon thefilm by the ordinary coagulating process. Such treatment of the filamentwith tri-sodium phosphate is preferably immediately followed by rinsingthe filament with water to eliminate therefrom the sulphur bearingimpurities thus rendered soluble. The filament may then be dried, pref-4 erably under tension.

As above contemplated, my invention includes any application of PO, ionsto coagulated or precipitated viscose, either before, or simultaneouslywith, the subjection of the same to the action of dye, and before suchproducts have been dried.

Therefore, I do not desire to limit all of my claims to the specificdetails of the procedure herein contemplated, as it is obvious thatvarious modifications may be made therein Without departing from theessen- 9 tial features of my invention, as defined. in the appendedclaims.

I claim: f 1. The method of manufacturing dyed articles from viscose(sulphocarbonate) which consists in subjecting viscose to the action ofa coagulating or precipitating element and then subjecting theprecipitated articles to the action of tri-sodium phosphate (NaPO,,) andof a dyeing element in the same aqueous solution, before drying sucharticles.

2. The method of manufacturing dyed articles from viscose(sulphocarbonate) which consists in subjecting viscose to the ltlUaction of a coagulating or precipitating element and thereaftercontemporaneously subjecting the precipitated articles to the action oft-ri -sodium phosphate (Na Po and a dyeing element beforeprimarilydrying such articles.

The method of manufacturing dyed articles from viscose which consists in00- agulating viscose to impure cellulose hydrate and thereaftercontemporaneously subject- 10 ing such coagulated product to the actionof a dyeing medium and of PO ions, before primarily drying sucharticles.

In testimony whereof, I have hereunto signed my name at Burlington, NewJersey, 15

this 20th day of May, 1925.

WVILLIAM MENDEL.

